Ambroxol hydrochloride (trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexanol hydrochloride) is an active substance from the category of expectorants, which is used in the treatment of acute and chronic diseases of the lower respiratory tract that are associated with disorders of the formation and transport of mucus, and is used for the relief of acute sore throats. Ambroxol hydrochloride is used in various formulations, for example as tablets for sucking, drops, syrup, tablets, delayed-release capsules, effervescent tablets or inhalable concentrate.
The commercially obtainable solid preparations of ambroxol usually consist of pellets produced by spray hardening and having an active substance content of about 35% by weight.
A disadvantage of this production method is the high dependency of the release of active substance on the particle size distribution, which in turn is strongly dependent on the spray parameters. This requires considerable effort to ensure the reproducibility of the release of active substance. Another disadvantage of the production method is the low content of active substance that can be achieved in the solid preparation, which is usually less than 35% as a result of spraying problems.